Medical researchers have determined that for exercise to be beneficial, a person’s desirable heart rate, R, in beats per minute, can be approximated by the formulas

R=143-0.65a for women
R=165-0.75a for men,

where a represents the person’s age. If the desirable heart rate for a man is 135 beats per minute, how old is he?
a.22.5 years old
b.40 years old
c.45 years old
d.42.5 years old



Evaluate the function
f(x)=1/2x+3

for f(4).
a. 5
b. 9
c. 11
d. 14